International Potato Center

About: International Potato Center is a facility organization based out in Lima, Peru. It is known for research contribution in the topics: Population & Phytophthora infestans. The organization has 1036 authors who have published 1460 publications receiving 47183 citations.

Tuber shape and eye depth variation in a diploid family of Andean potatoes

Abstract: Tuber appearance is highly variable in the Andean cultivated potato germplasm The diploid backcross mapping population ‘DMDD’ derived from the recently sequenced genome ‘DM’ represents a sample of the allelic variation for tuber shape and eye depth present in the Andean landraces Here we evaluate the utility of morphological descriptors for tuber shape for identification of genetic loci responsible for the shape and eye depth variation Subjective morphological descriptors and objective tuber length and width measurements were used for assessment of variation in tuber shape and eye depth Phenotypic data obtained from three trials and male–female based genetic maps were used for quantitative trait locus (QTL) identification Seven morphological tuber shapes were identified within the population A continuous distribution of phenotypes was found using the ratio of tuber length to tuber width and a QTL was identified in the paternal map on chromosome 10 Using toPt-437059, the marker at the peak of this QTL, the seven tuber shapes were classified into two groups: cylindrical and non-cylindrical In the first group, shapes classified as ‘compressed’, ‘round’, ‘oblong’, and ‘long-oblong’ mainly carried a marker allele originating from the male parent The tubers in this group had deeper eyes, for which a strong QTL was found at the same location on chromosome 10 of the paternal map The non-cylindrical tubers classified as ‘obovoid’, ‘elliptic’, and ‘elongated’ were in the second group, mostly lacking the marker allele originating from the male parent The main QTL for shape and eye depth were located in the same genomic region as the previously mapped dominant genes for round tuber shape and eye depth A number of candidate genes underlying the significant QTL markers for tuber shape and eye depth were identified Utilization of a molecular marker at the shape and eye depth QTL enabled the reclassification of the variation in general tuber shape to two main groups Quantitative measurement of the length and width at different parts of the tuber is recommended to accompany the morphological descriptor classification to correctly capture the shape variation

Identification of triplex (YYYy) Potato Virus Y (PVY) immune progenitors derived fromSolanum tuberosum ssp.andigena

Abstract: As part of the International Potato Center’s (CIP) virus resistance breeding strategy, a group of 182 selected clones from intercrosses among duplex Potato Virus Y (PVY) immune progenitors derived fromSolanum tuberosum ssp.andigena (i.e., YYyy × YYyy) was sampled. These clones were test-crossed to the PVY susceptible tester 377964.5 (yyyy) to search for triplex (YYYy) and quadruplex (YYYY) PVY immune potato progenitors. Seedlings of each test-crossed progeny were screened for PVY immunity. Genetic analysis of observed ratios for immunity-susceptibility showed that two of the 182 clones segregated as triplex under the assumption of a random chromatid segregation model. The double reduction coefficient, α, and its standard error were estimated from the experimental data, and had values of 0.1566 and 0.0186 respectively. These results indicated that crossovers take place during meiosis between the locus and the centromere, permitting sister chromatids to migrate to the same pole producing a random chromatid segregation. In the population evaluated, no clone was identified as a quadruplex. The two triplex PVY immune genotypes will produce about 96% of progenies with PVY immunity when mated to PVY susceptible advanced clones or varieties. These progenitors have the potential to provide a durable PVY genetic control and diminish the present impact of this virus on the potato crop. Also, immunity to PVY will significantly simplify the seed production process.

Glucosinolate survey of cultivated and feral mashua (Tropaeolum tuberosum Ruíz & PavÓn) in the Cuzco region of Peru

Abstract: Glucosinolates (GSL) present in cultivated and feral accessions of mashua (Tropaeolum tuberosum Ruiz & Pavon) were identified and quantified by High Performance Liquid Chromatography (HPLC) analysis. The main glucosinolates detected were aromatic: 4–Hydroxybenzyl GSL (OHB, Glucosinalbin), Benzyl GSL (B, Glucotropaeolin), and m–Methoxybenzyl GSL (MOB, Glucolimnathin). The total amount of GSL observed ranged from 0.27 to 50.74 micromols per gram (μMol/g) of dried tuber tissue. Most of the low-content GSL accessions are distributed within the cultivated population with a total GSL concentration lower than 5.00 μMol/g of dried tuber tissue. The highest total and specific GSL (OHB, B, and MOB) contents (more than 25.00 μMol/g of dried tuber tissue) were observed in the feral population with few exceptions. In addition, only six different GSL profiles were found: Only MOB; only B; OHB and B; OHB and MOB; B and MOB; and OHB, B and MOB.

Factors affecting farmers' willingness and ability to adopt and retain vitamin A-rich varieties of orange-fleshed sweet potato in Mozambique.

Abstract: The addition of orange-fleshed sweet potato (OFSP) to the food environment is an effective nutrition-sensitive agricultural approach to improve vitamin A intakes. However, the adoption of this biofortified crop merits further study. The objective of our research was to understand factors that affect Mozambican farmers’ adoption and retention of OFSP varieties, with a specific interest in the retention of planting material. Field research was conducted in three provinces of Mozambique during 2015. Provinces with different OFSP intervention histories were selected to allow for the identification of site-specific factors and the impact of variable approaches over time. Qualitative inquiry was used to assess participants’ progress through the five stages of the Innovation-Decision process in the Diffusion of Innovations Theory. Ninety-five producers, consumers, and market stakeholders of OFSP participated in semi-structured in-depth interviews and focus groups. Results indicate that diverse factors influenced the adoption and retention of OFSP, including organoleptic qualities, taste preferences, access to planting material, agronomic traits, environmental conditions, lack of capital for inputs and labor, unstable markets, and limited sharing of information and planting material across farmer networks. Current OFSP varieties were acceptable to Mozambican farmers and consumers, but there are several remaining challenges to reaching a critical mass such as lack of access to planting material, perceptions of superior drought tolerance of white-fleshed sweet potato (WFSP), and the belief that OFSP requires additional effort to cultivate (e.g. weed removal, measuring space between plants). Key recommendations which may be considered in future planning for OFSP interventions in Mozambique and other countries include enabling decentralized vine multipliers to provide vines to community members at no cost, continued focus on breeding and distribution of more drought tolerant varieties of OFSP, and training on the similarities in agronomic practices required for producing and preserving OFSP and WFSP.